Reversing alarm



FIG. 1 is a top plan view of my design for a reversing alarm;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a front elevation view thereof; and,

FIG. 5 is a right side elevation view thereof. 

The ornamental design for a reversing alarm, as shown and described. 